In this specification where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date publicly available, known to the public, part of the common general knowledge or known to be relevant to an attempt to solve any problem with which this specification is concerned.
Adjuvants are used in agriculture to assist the performance of agrochemicals such as herbicides, insecticides, fungicides, growth promoters etc. Many different classes of chemicals are used as adjuvants to assist the agrochemical in different ways. For example:                oils for foliar penetration or to reduce evaporation,        surfactants (often also called emulsifiers) for surface wetting, coverage and/or penetration,        buffering agents for protecting sensitive agrochemicals, and        ammonium salts to provide hard water protection, promote compatibility and stimulate plant uptake of agrochemicals.        
When preparing a mixture for spraying, an applicator may need more than one class of adjuvant and thus create a complex tank mix containing multiple adjuvant products and crop protection product(s). This can lead to problems such as incompatibility between the various products added to the spray tank or other unforeseen problems such as crop damage or toxicity to non-target organisms.
Recently, products which combined two or more classes of adjuvant have been made available. One such product combining lipophilic solvent (oil) and lipophobic plant nutrient (ammonium salt) is described by U.S. Pat. No. 7,314,848 which uses cationic surfactants to form a homogeneous liquid composition suitable as an agrochemical adjuvant, particularly for use with the herbicide glyphosate.
While cationic surfactants are powerful surfactants for a number of reasons, they are not the most desirable surfactants for use in agrochemical formulations. The use of cationic surfactants may increase the risk of tank mix incompatibility, foaming, driftable fines, crop phytotoxicity and toxicity to non-target organisms, such as beneficial insects, birds and aquatic life.
A liquid emulsion adjuvant product needs to be convenient to use (pourable and dispersible into water) and have a shelf-life (no substantial change) of at least a few months, and preferable greater than one year, to be useful. That is, such liquid emulsion products need to be stable, pourable and dispersible into water.
Generally, the amount of surfactant required to produce such a stable, pourable and dispersible liquid emulsion adjuvant product is related to the proportion of oil in the formulation. As a result, a higher proportion of surfactant is required to produce a stable emulsion containing a higher proportion of oil than emulsion containing a lower amount of oil. Further, an even higher proportion of surfactant is required to produce a stable emulsion if the aqueous phase contains electrolytes than an equivalent electrolyte-free formulation. For example, prior art formulations containing oil and saturated or nearly saturated solutions of ammonium salts using surfactants involve:                a proportion of surfactant (both oil compatible and water soluble electrolyte tolerant surfactants) to oil which is generally greater than 1:1, and is always greater than 2:3 (US2008127661; see examples);        a proportion of surfactant to oil of more than 1:1 (US20030125211 and US20070032382, see examples); and        a proportion of surfactant (combination of nonionic and anionic surfactants) to oil of at least 1:2 (WO99/55645, see examples containing more concentrated ammonium salt solution (more than 5%)).        
There is thus a need for improved adjuvant formulations which combine oils and ammonium onium salts in a form suitable for use as an agricultural adjuvant, but which also minimize the amount of powerful or harsh surfactants used, and thus reduce the detrimental effects of such surfactants.